1. Technical Field
The present disclosure relates to surgical fastener applying apparatus, and more particularly, to an anvil assembly for use therewith, as well as methods of manufacturing the same.
2. Background of the Related Art
Many varieties of surgical fastener applying apparatus are known in the art, some of which are specifically adapted for use in various surgical procedures such as end-to-end anastomosis, circular end-to-end anastomosis, open gastrointestinal anastomosis, endoscopic gastrointestinal anastomosis, and transverse anastomosis. Suitable examples of fastener applying apparatus that may be used during the course of such procedures can be seen in U.S. Pat. Nos. 5,915,616; 6,202,914; 5,865,361; and 5,964,394.
Surgical fastener applying apparatus for use in performing circular anastomosis of hollow tissue organs generally include an anvil assembly incorporating an anvil head and an anvil plate. The anvil plate includes pockets that are configured and dimensioned to receive and form the surgical fasteners to join together adjacent sections of the patient's tissue. The fastener pockets are typically arranged into one or more rows positioned on opposite sides of, or about, a cutting element or a corresponding channel adapted for the receipt of the cutting element.
In these apparatus, the anvil head and the anvil plate are often assembled through welding, by forming retention tabs over the anvil plate and staking the anvil head and the anvil plate together, or by swaging a rib over the anvil plate. However, when the anvil head and the anvil plate are formed from different materials, welding may be inapplicable, while staking and swaging of the aforementioned rib may result in the formation of a protrusion that may in certain instances affect tissue clamped between the anvil head and the anvil plate.
When surgical fasteners are applied to tissue, proper formation is desirable for many different reasons, including the minimization of bleeding and the effectuation of hemostasis. In order to ensure accurate and consistent formation of surgical fasteners, considerable research and development has been conducted in the areas of forming and driving structures, and strict manufacturing tolerances have been implemented. For example, anvil assemblies such as those described in U.S. Pat. Nos. 5,173,133 and 5,480,089 have been developed with specific coatings and/or structure, and fastener cartridges such as those described in commonly assigned U.S. Pat. No. 4,978,049 include driver structure that is configured and dimensioned to balance forces encountered during staple formation.
Consequently, it would be advantageous to provide an anvil assembly for use with a surgical fastener applying apparatus that includes an anvil head and an anvil plate formed from different materials and incorporating design features that will address these issues of manufacture and fastener formation.